Fundamental role of Σ3(1¯11) and Σ3(1¯12) grain boundaries in elastic response and slip transfer

2011 ◽  
Vol 110 (7) ◽  
pp. 073520 ◽  
Author(s):  
T. Tsuru ◽  
Y. Kaji ◽  
Y. Shibutani
Keyword(s):  
Grain Boundaries ◽  
Elastic Response ◽  
Slip Transfer

scholarly journals The role of slip transfer at grain boundaries in the propagation of microstructurally short fatigue cracks in Ni-based superalloys

2019 ◽  
Vol 162 ◽  
pp. 261-265 ◽  
Author(s):  
M. Jiménez ◽  
W. Ludwig ◽  
D. Gonzalez ◽  
J.M. Molina-Aldareguia
Keyword(s):  
Grain Boundaries ◽  
Fatigue Cracks ◽  
Slip Transfer

Elucidation of block boundaries as the dissolution channels in hydrated cement

1978 ◽  
Vol 36 (1) ◽  
pp. 484-485
Author(s):  
N.V. Belov ◽  
U.I. Papiashwili ◽  
B.E. Yudovich
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Benzoyl Peroxide ◽  
Phase Contrast ◽  
Active Role ◽  
Point Of View ◽  
Hardened Cement ◽  
Hydrated Cement ◽  
Hardened Cement Paste

It has been almost universally adopted that dissolution of solids proceeds with development of uniform, continuous frontiers of reaction.However this point of view is doubtful / 1 /. E.g. we have proved the active role of the block (grain) boundaries in the main phases of cement, these boundaries being the areas of hydrate phases' nucleation / 2 /. It has brought to the supposition that the dissolution frontier of cement particles in water is discrete. It seems also probable that the dissolution proceeds through the channels, which serve both for the liquid phase movement and for the drainage of the incongruant solution products. These channels can be appeared along the block boundaries.In order to demonsrate it, we have offered the method of phase-contrast impregnation of the hardened cement paste with the solution of methyl metacrylahe and benzoyl peroxide. The viscosity of this solution is equal to that of water.

Carbide precipitation and chromium depletion on coherent twin boundaries in deformed 304 stainless steels

1992 ◽  
Vol 50 (2) ◽  
pp. 1216-1217
Author(s):  
A.H. Advani ◽  
L.E. Murr ◽  
D.J. Matlock ◽  
W.W. Fisher ◽  
P.M. Tarin ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Stainless Steels ◽  
Interfacial Free Energy ◽  
Carbide Precipitation ◽  
Twin Boundaries ◽  
Invariant Structure ◽  
Heat Treated ◽  
Constant Structure ◽  
Cr Depletion

Coherent annealing-twin boundaries are constant structure and energy interfaces with an average interfacial free energy of ∼19mJ/m2 versus ∼210 and ∼835mJ/m2 for incoherent twins and “regular” grain boundaries respectively in 304 stainless steels (SS). Due to their low energy, coherent twins form carbides about a factor of 100 slower than grain boundaries, and limited work has also shown differences in Cr-depletion (sensitization) between twin versus grain boundaries. Plastic deformation, may, however, alter the kinetics and thermodynamics of twin-sensitization which is not well understood. The objective of this work was to understand the mechanisms of carbide precipitation and Cr-depletion on coherent twin boundaries in deformed SS. The research is directed toward using this invariant structure and energy interface to understand and model the role of interfacial characteristics on deformation-induced sensitization in SS. Carbides and Cr-depletion were examined on a 20%-strain, 0.051%C-304SS, heat treated to 625°C-4.5h, as described elsewhere.

Kesterite Thin‐Film Solar Cell: Role of Grain Boundaries and Defects in Copper–Zinc–Tin–Sulfide and Copper–Zinc–Tin–Selenide

2021 ◽  
pp. 2100039
Author(s):  
Lingam Sravani ◽  
Soumyaranjan Routray ◽  
Kumar Prasannajit Pradhan ◽  
Maykel Courel Piedrahita
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Grain Boundaries ◽  
Thin Film Solar Cell ◽  
Tin Sulfide ◽  
Copper Zinc Tin Sulfide ◽  
Tin Selenide ◽  
Copper Zinc

scholarly journals Internal melt figures in ice by rapid adiabatic compression

1994 ◽  
Vol 40 (134) ◽  
pp. 132-134
Author(s):  
R.E. Gagnon ◽  
C. Tulk ◽  
H. Kiefte
Keyword(s):  
Phase Transformations ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Adiabatic Compression ◽  
Air Bubbles ◽  
Water Ice ◽  
Deep Focus ◽  
And Behavior ◽  
First Time

AbstractSingle crystals and bicrystals of water ice have been adiabatically pressurized to produce, and clearly illustrate, two types of internal melt figures: (1) dendritic figures that grow from nucleation imperfections on the specimen’s surface, or from air bubbles at grain boundaries, into the ice as pressure is elevated; and (2) compression melt fractures, flat liquid-filled disks, that nucleate at imperfections in the crystal and grow with the application of pressure eventually to sprout dendritic fingers at the periphery. The transparency of the ice permitted visualization of the growth and behavior of the figures, and this could be an important tool in understanding the role of phase transformations in deep-focus earthquakes. Correlation between figure size and pressure is noted for the first time.

scholarly journals Role of Grain Boundaries in diffusional Phenomena during Gas Nitriding of Pure Iron

2011 ◽  
Vol 10 ◽  
pp. 2943-2948 ◽  
Author(s):  
S. Fare ◽  
N. Lecis ◽  
E. Brescia ◽  
M. Mazzola
Keyword(s):  
Grain Boundaries ◽  
Pure Iron ◽  
Gas Nitriding

Microstructure of Polycrystalline MgO Penetrated by a Silicate Liquid

1996 ◽  
Vol 2 (3) ◽  
pp. 113-128 ◽  
Author(s):  
Sundar Ramamurthy ◽  
Michael P. Mallamaci ◽  
Catherine M. Zimmerman ◽  
C. Barry Carter ◽  
Peter R. Duncombe ◽  
...  
Keyword(s):  
Grain Boundaries ◽  
Grain Growth ◽  
Glassy Phase ◽  
Silicate Liquid ◽  
Two Phase ◽  
The Matrix ◽  
Devitrification Process ◽  
Phase Mixture

Dense, polycrystalline MgO was infiltrated with monticellite (CaMgSiO4) liquid to study the penetration of liquid along the grain boundaries of MgO. Grain growth was found to be restricted with increasing amounts of liquid. The inter-granular regions were generally found to be comprised of a two-phase mixture: crystalline monticellite and a glassy phase rich in the impurities present in the starting MgO material. MgO grains act as seeding agents for the crystallization of monticellite. The location and composition of the glassy phase with respect to the MgO grains emphasizes the role of intergranular liquid during the devitrification process in “snowplowing” impurities present in the matrix.

Virtual trabecular bone models and their mechanical response

2008 ◽  
Vol 222 (8) ◽  
pp. 1185-1195 ◽  
Author(s):  
F E Donaldson ◽  
P Pankaj ◽  
A H Law ◽  
A H Simpson
Keyword(s):  
Finite Element ◽  
Trabecular Bone ◽  
Mechanical Behaviour ◽  
Mechanical Response ◽  
Elastic Response ◽  
Anatomical Site ◽  
Virtual Samples ◽  
Micro Level ◽  
Architectural Characteristics

The study of the mechanical behaviour of trabecular bone has extensively employed micro-level finite element (μFE) models generated from images of real bone samples. It is now recognized that the key determinants of the mechanical behaviour of bone are related to its micro-architecture. The key indices of micro-architecture, in turn, depend on factors such as age, anatomical site, sex, and degree of osteoporosis. In practice, it is difficult to acquire sufficient samples that encompass these variations. In this preliminary study, a method of generating virtual finite element (FE) samples of trabecular bone is considered. Virtual samples, calibrated to satisfy some of the key micro-architectural characteristics, are generated computationally. The apparent level elastic and post-elastic mechanical behaviour of the generated samples is examined: the elastic mechanical response of these samples is found to compare well with natural trabecular bone studies conducted by previous investigators; the post-elastic response of virtual samples shows that material non-linearities have a much greater effect in comparison with geometrical non-linearity for the bone densities considered. Similar behaviour has been reported by previous studies conducted on real trabecular bone. It is concluded that virtual modelling presents a potentially valuable tool in the study of the mechanical behaviour of trabecular bone and the role of its micro-architecture.

Role of the solid/liquid interface faceting in rapid penetration of a liquid phase along grain boundaries

2001 ◽  
Vol 49 (7) ◽  
pp. 1123-1128 ◽  
Author(s):  
D. Chatain ◽  
E. Rabkin ◽  
J. Derenne ◽  
J. Bernardini
Keyword(s):  
Liquid Phase ◽  
Grain Boundaries ◽  
Liquid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid
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